A wireless communication system is a multiple access system. In the wireless communication system, a base station sends, on a downlink, downlink data and/or control information to a user equipment (UE), and receives, on an uplink, uplink data and/or control information sent by the user equipment. Communication between the base station and the user equipment may be performed by using a frequency division duplex (FDD) manner or a time division duplex (TDD) manner.
Generally, when two user equipments need to communicate with each other, a source user equipment first needs to transmit data to a base station or a network, and then the base station or the network transmits the received data to a destination user equipment. In order to increase a capacity of a communication system to satisfy a requirement of the user equipment for high speed services, user equipments close to each other may directly perform data transmission, thereby reducing an overhead of a transmission resource, such as time, a frequency, a code channel, and power, between the user equipment and the base station; and a transmission resource may be multiplexed between different user equipments far away from each other, thereby further increasing resource utilization efficiency, and improving a throughput of the system.
In the prior art, the base station only allocates transmission resources for communication between the base station and the user equipment, and determines, according to an uplink service load and a downlink service load, allocation of an uplink transmission resource and a downlink transmission resource for the communication. However, in an existing transmission resource allocation method, transmission resources for direct communication between user equipments are not considered.